Manual

-77-
Project 145
Morse Code
With a few changes, the preceding
circuit can be used to send messages.
replace the slide switch (S1) with the
press switch (S2), and modify the
connections to the light tunnel (U30) as
shown. Push the press switch several
times to send messages using Morse
Code.
Project 146
Tower of Lights
Use the project 145 circuit, but replace the light
tunnel (U30) with the white & color LEDs (D6 &
D8), as shown. Push on the press switch (S2) to
light the LEDs.
Send messages to your friends using Morse
Code, as described in project 145.
Morse Code: The forerunner of today’s telephone system was the
telegraph, which was widely used in the latter half of the 19th century. It
only had two states - on or off (that is, transmitting or not transmitting),
and could not send the range of frequencies contained in human voices
or music. A code was developed to send information over long distances
using this system and a sequence of dots and dashes (short or long
transmit bursts). It was named Morse Code after its inventor. It was also
used extensively in the early days of radio communications, though it
isn’t in wide use today. It is sometimes referred to in Hollywood movies,
especially Westerns. Modern communications systems send data across
the country using similar coding systems, but at much higher speeds.
MORSE CODE
A . _
B _ . . .
C _ . _ .
D _ . .
E .
F . . _ .
G _ _ .
H . . . .
I . .
J . _ _ _
K _ . _
L . _ . .
M _ _
N _ .
O _ _ _
P . _ _ .
Q _ _ . _
R . _ .
S . . .
T _
U . . _
V . . . _
W . _ _
X _ . . _
Y _ . _ _
Z _ _ . .
Period
. _ . _ . _
Comma _ _ . . _ _
Question . . _ _ . .
1 . _ _ _ _
2 . . _ _ _
3 . . . _ _
4 . . . . _
5 . . . . .
6 _ . . . .
7 _ _ . . .
8 _ _ _ . .
9 _ _ _ _ .
0 _ _ _ _ _